I think that there are a lot of scams because cryptocurrency is anonymity. It is possible to conduct scam ICO collect money and do not have any punishment at all. Such unpunishment provocates people to create new scams.
Most blockchains are transparent. All token platforms allow you to track any transaction. Impunity for fraudsters lies not in the anonymity of cryptocurrencies, but in the absence of laws. ICO is not a contract and there are no guarantees. ICO is a raising of voluntary investments in exchange for team promises. It would be surprising if the scammers did not use it.
Because of impunity of fraudsters people lose their trust to cryptocurrency. Everybody can steal your money and do not have any punishment.